Improvement in dynamic wrenches



S. PLYMALE.

Dynamic Wrench.

* Pat entedjune 8,l875.

/ Z72 rem Z0 z".

- TH GRAPHIC C(LPHOTO LITH 398; P K P CE N Y UNITED STATES PATENTOFFICE.

SEBASTIAN PLYMALE, OF PORTLAND, OREGON.

IMPROVEMENTIN DYNAMIC WRENCHES.

Specification forming part of Letters PatentNo. 164, 100, dated June8,-1875 application filed February 25, 1875.

To all whom it may concern:

Be it known that I, SEBASTIAN PLYMALE, of Portland, in the county ofMultnomah, in the State of Oregon, have invented an Improvement inDynamic Wrenches, of which the following is a specification:

My invention consists in the application of certain levers, springs,850., 'to a movable ratchet held in the case of a wrench and consists,substantially, of the parts represented in the drawings by Figs. 1 and2.

Figurel shows a section in a lateral and longitudinal manner through themiddle of the wrench-case, and Fig. 2 shows the exterior of the samewith the indicator, dial, 850.

The ratchet A has in its center a square five or six side mortise,corresponding to the bolthead or nut to be used. The ratch-cuts do notrun entirely across the face of the piece A, but are made in such a waythat a web'is left on either edge, forming a cylindrical bearing, andfitting into the case J neatly, or in such a way that it may turn freelyin it when a vibratory motion is given it by the handle screwed into thesmaller end; also, in the piece A a number of small round holes arebored, into which the pin M fits for certain uses. B is a pawl, whoseback end forms a fulcrum, against which one end of the lever D works,and is connected to D by'a link, 0. In the larger end ofD a shortrock-shaft-isformed in the solid casing, whose ends are held by thewrench-case J, and at the smaller end of D a second fulcrum, E, isplaced loosely between the levers D and F. The circumferential end of Fisformed into a circular rack, which engages with the index-pinion G.

The weighing-spring H presses the whole system of levers and fulcrumsfirmly together and against the adjusting-screw L. In addition to thesea small U-shaped spring is used to press the pawl B into theratch. Bymeans of these parts the index p ipion G gives motion to the indicatoron the face of the dial I, Fig. 2.

The screw L is used to set the indicator at any given number of pounds,when the wrench is used as an ordinary wrench, until the pressurebecomes great enough to move the indicator. As soon as this is noticedthe opera tion of turning the nut ceases, as it shows that the desiredtension on the bolt has been reached.

The strength of the spring H is ascertained by experiment, and the dialI graduated accordingly.

Simply turning the screw L compresses the spring H, and at the same timeturns the indicator, showing the number of pounds represented by thecompression, and, as a matter of course, the'force represented inturning the handle of the wrench, and communicated through the pawl B tothe ratch A, is instantly registered, when the force used in turningbecomes greater than the influence of the spring H acting against thelevers F and D.

Screws K hold the face of the case on.

This wrench is useful wherever nuts and screws are used, as, by means ofit, bolts may be made to carry a uniform load, and the exact weight orpressure they are holding ascertained in pounds; more especially usefulin the case, of suspension rods of bridges,- roofs, and suspendedstructures; for ascertaining the strain on cables attached to screws,orcapstans fitted for this purpose.

When it is desired to fix the ratch A firmly in the case J, the pin=M isinserted in one of the holes in ratch A, and turned partially round, oruntil a groove cut across the pin looks it fast behind the wire N Tounloose it the operation is reversed, and a spiral spring around the pinM, and between the milled head of M and the wrench-case, returns it toits first or unengaged position.

The wear of any of the parts will not essentially interfere with theweighing apparatus, as all such wear is compensated by means of thespring H and the screw-pin L, against which the system bears.

I claim- The ratch A, pawl B, link 0, levers D and F, fulcrum E, springH, screw L, and pin M, operating in a case, J, on an indicator, G, overa dial, I, substantially as described, and for the purpose set forth.

SEBASTIAN PLYMALE.

Witnesses:

GHAs. B. TALBOT, Rrcnn. M. TABon.

